The present invention relates to a device and to a method for the surface peening, in particular ultrasonic shot peening, of a component of a gas turbine of the type indicated in the preambles of patent claims 1 and 12.
Such a device and such a method are already known from EP 1 101 568 B1, in which the rotor blades of a rotor fashioned as a blisk can be shot-peened in order to improve fatigue strength. The device comprises a holding device with which the rotor is mounted so as to be capable of rotation about its axis of rotation. Through the rotation of the rotor, its rotor blades are guided through a peening chamber on the lower side of which is fastened a vibration device in the form of an ultrasonic sonotrode having a surface that runs at least approximately horizontally and that impinges or accelerates the blasting material. The peening chamber is thus bounded both axially, i.e. in the area of the broad sides of the rotor, and also radially, i.e. in the area of the rotor blades, relative to the blisk by corresponding chamber walls. Because in particular the chamber walls of the peening chamber that are positioned radially to the rotor are not able, depending on the position of the respective rotor blades, to hold all the shot inside the central peening chamber, two additional chambers are situated before and after this chamber, in the radial direction of the rotor. Inside these additional chambers, shot spilling out from the central peening chamber, which is equipped with the sonotrode, is collected and led back via corresponding channels.
However, a problem with this device and this method is the fact that components having complex shapes are difficult to strengthen in a uniform manner. This is true in particular for surface areas of the component that are not positioned parallel to the vibrating surface of the vibration device, or that are moved into such a position.